The invention relates to a new single-spool weave for face-to-face weaving by which color mixing is avoided.
Single spool or single shuttle weaving for face-to-face pile fabrics is a weaving process whereby in successive machine cycles one weft is alternately inserted in bottom fabric and in top fabric, by forming alternately consecutive single sheds for the bottom, then for the top fabric. By this weaving method, the pile yarns need only be raised or lowered in two positions for both working pile and incorporation of dead pile: (1) under the weft (bottom position) or (2) above the weft (top position). A typical feature of this weaving method is that each weft yarn carries a pile row.
More particularly, in the case of single-spool weaves with bound-in dead pile, in which a binder warp working in a two shot up--two shot down sequence (referred to as 2/2) and a tension warp working in a one shot up--one shot down sequence (referred to as 1/1) are used, a certain mixing of the colors always occurs. This mixing is due to the fact that pile threads of a different color lie between two inner shots. This problem, which underlies this invention, is illustrated in the prior art FIGS. 1-5. As is well-known in the art, in face-to-face weaving it is necessary to weave together a top fabric portion and a bottom fabric portion to produce a final product. Both the top fabric portion and the bottom fabric portion have bound-in dead pile, which is bound by inner and outer weft thread alternately disposed in the top and bottom fabric. The top fabric and the bottom fabric have two levels respectively, the backside and the pile side. The inner shots are disposed between the top and bottom fabrics, and the outer shots are disposed outside the top and bottom fabrics. As can be seen in FIGS. 1-5, the inner shots are numbered 1, 4, 5 and 8; and the outer shots are numbered 2, 3, 6 and 7.
FIG. 1 shows diagrammatically a single-spool woven face-to-face fabric, in which the weave of the active pile threads is a 1/1 weave, and in which a pile thread 9 which was active over the first four shots 1, 2, 3, 4 is bound into the bottom fabric 30 after the fourth shot 4, and another pile thread 10 which was previously bound into the bottom fabric 30 becomes active pile thread after the fourth shot 4. In the top fabric 32, both pile thread 9 and pile thread 10 appear between shot 3 and shot 5. The differing colors of the two pile threads mean that color mixing is obtained at that place in the top fabric. As is well-known in the art, as shot 3 is located on the back of the top fabric 32 and shot 5 is located at the pile side of the top fabric 32 by the separation of the tension warp 34, the action of the binder warp 36 is that shot 5 tends to lie under shot 3. When the top and bottom fabrics are afterwards separated by the diagrammatically illustrated cutter blades 38, because the cut end of pile thread 10 of the top fabric has a color different from the cut end of pile thread 9 of the top fabric, a color mixing effect results. The color contour is not neat and this is particularly objectionable when a color transition between two color fields has to be made to form one pile row with tuft of same color which should appear in the pattern as a color line extending in weft-wise direction.
FIG. 2 again shows a single-spool woven face-to-face fabric with a 1/1 V-weave for the active pile threads, in which a pile thread 11 which was active over the first four shots 1, 2, 3, 4 is bound into the top fabric after the fourth shot 4, and another pile thread 12 which was previously bound into the top fabric becomes active pile thread after the fourth shot 4. In the bottom fabric, both pile thread 11 and pile thread 12 appear between shot 4 and shot 6. Their differing colors mean that color mixing is obtained at that place in the bottom fabric. Although in FIG. 2, a crossing point of binding warp lies between shot 4 and shot 6, shot 4 tends to lie above shot 2, allowing shot 6 to lie along shot 2, with the consequence that the pile leg 5 to 6 of the end 12 coincides with leg 4 to 5 of pile thread 11. As the two legs of different color both lie between shots 4 and 6, it is well-known that color mixing would occur. It is also well-known that there would be no color mixing between shots 6 and 7, however, because shots 6 and 7 belong to the bottom and top fabrics, respectively, and pile thread 11 is bound to the top fabric after shot 5.
FIG. 4 shows a single-spool woven face-to-face fabric with a 1/1 V-weave for the active pile threads, in which a pile thread 13 which was active over the first four shots 1, 2, 3, 4 is bound into the top fabric after the fourth shot 4, and another pile thread 14 which was previously bound into the bottom fabric becomes active pile thread after the fourth shot 4. In the bottom fabric, both pile thread 13 and pile thread 14 appear between shot 4 and shot 5. These two pile threads 13 and 14, referred to as "double workers", run below shot 4 in the bottom fabric to above shot 5 in the top fabric. Even if, according to a known method (see FIG. 5), the double workers of FIG. 4 are not utilized, a color mixing still occurs at the level of shot 4.
A known solution to the problem of color mixing is that only a 1/1 weave is used for the base weave. The inlaid yarns consequently come to lie less above one another, and a better alignment between the different color fields is obtained. A disadvantage of this is, however, that the back of the fabrics becomes less attractive, due to the fact that the inlaid yarns cannot lie as closely together.